| 1 | class MarseilleRules extends ChessRules |
| 2 | { |
| 3 | static IsGoodEnpassant(enpassant) |
| 4 | { |
| 5 | if (enpassant != "-") |
| 6 | { |
| 7 | const squares = enpassant.split(","); |
| 8 | if (squares.length > 2) |
| 9 | return false; |
| 10 | for (let sq of squares) |
| 11 | { |
| 12 | const ep = V.SquareToCoords(sq); |
| 13 | if (isNaN(ep.x) || !V.OnBoard(ep)) |
| 14 | return false; |
| 15 | } |
| 16 | } |
| 17 | return true; |
| 18 | } |
| 19 | |
| 20 | getTurnFen() |
| 21 | { |
| 22 | if (this.startAtFirstMove && this.moves.length==0) |
| 23 | return "w"; |
| 24 | return this.turn + this.subTurn; |
| 25 | } |
| 26 | |
| 27 | // There may be 2 enPassant squares (if 2 pawns jump 2 squares in same turn) |
| 28 | getEnpassantFen() |
| 29 | { |
| 30 | const L = this.epSquares.length; |
| 31 | if (this.epSquares[L-1].every(epsq => epsq === undefined)) |
| 32 | return "-"; //no en-passant |
| 33 | let res = ""; |
| 34 | this.epSquares[L-1].forEach(epsq => { |
| 35 | if (!!epsq) |
| 36 | res += V.CoordsToSquare(epsq) + ","; |
| 37 | }); |
| 38 | return res.slice(0,-1); //remove last comma |
| 39 | } |
| 40 | |
| 41 | setOtherVariables(fen) |
| 42 | { |
| 43 | const parsedFen = V.ParseFen(fen); |
| 44 | this.setFlags(parsedFen.flags); |
| 45 | if (parsedFen.enpassant == "-") |
| 46 | this.epSquares = [ [undefined,undefined] ]; |
| 47 | else |
| 48 | { |
| 49 | let res = []; |
| 50 | const squares = parsedFen.enpassant.split(","); |
| 51 | for (let sq of squares) |
| 52 | res.push(V.SquareToCoords(sq)); |
| 53 | if (res.length == 1) |
| 54 | res.push(undefined); //always 2 slots in epSquares[i] |
| 55 | this.epSquares = [ res ]; |
| 56 | } |
| 57 | this.scanKingsRooks(fen); |
| 58 | // Extract subTurn from turn indicator: "w" (first move), or |
| 59 | // "w1" or "w2" white subturn 1 or 2, and same for black |
| 60 | const fullTurn = V.ParseFen(fen).turn; |
| 61 | this.startAtFirstMove = (fullTurn == "w"); |
| 62 | this.turn = fullTurn[0]; |
| 63 | this.subTurn = (fullTurn[1] || 1); |
| 64 | } |
| 65 | |
| 66 | getPotentialPawnMoves([x,y]) |
| 67 | { |
| 68 | const color = this.turn; |
| 69 | let moves = []; |
| 70 | const [sizeX,sizeY] = [V.size.x,V.size.y]; |
| 71 | const shiftX = (color == "w" ? -1 : 1); |
| 72 | const firstRank = (color == 'w' ? sizeX-1 : 0); |
| 73 | const startRank = (color == "w" ? sizeX-2 : 1); |
| 74 | const lastRank = (color == "w" ? 0 : sizeX-1); |
| 75 | const pawnColor = this.getColor(x,y); //can be different for checkered |
| 76 | const finalPieces = x + shiftX == lastRank |
| 77 | ? [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN] |
| 78 | : [V.PAWN]; |
| 79 | |
| 80 | // One square forward |
| 81 | if (this.board[x+shiftX][y] == V.EMPTY) |
| 82 | { |
| 83 | for (let piece of finalPieces) |
| 84 | { |
| 85 | moves.push(this.getBasicMove([x,y], [x+shiftX,y], |
| 86 | {c:pawnColor,p:piece})); |
| 87 | } |
| 88 | // Next condition because pawns on 1st rank can generally jump |
| 89 | if ([startRank,firstRank].includes(x) |
| 90 | && this.board[x+2*shiftX][y] == V.EMPTY) |
| 91 | { |
| 92 | // Two squares jump |
| 93 | moves.push(this.getBasicMove([x,y], [x+2*shiftX,y])); |
| 94 | } |
| 95 | } |
| 96 | // Captures |
| 97 | for (let shiftY of [-1,1]) |
| 98 | { |
| 99 | if (y + shiftY >= 0 && y + shiftY < sizeY |
| 100 | && this.board[x+shiftX][y+shiftY] != V.EMPTY |
| 101 | && this.canTake([x,y], [x+shiftX,y+shiftY])) |
| 102 | { |
| 103 | for (let piece of finalPieces) |
| 104 | { |
| 105 | moves.push(this.getBasicMove([x,y], [x+shiftX,y+shiftY], |
| 106 | {c:pawnColor,p:piece})); |
| 107 | } |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | // En passant: always OK if subturn 1, |
| 112 | // OK on subturn 2 only if enPassant was played at subturn 1 |
| 113 | // (and if there are two e.p. squares available). |
| 114 | const Lep = this.epSquares.length; |
| 115 | const epSquares = this.epSquares[Lep-1]; //always at least one element |
| 116 | let epSqs = []; |
| 117 | epSquares.forEach(sq => { |
| 118 | if (!!sq) |
| 119 | epSqs.push(sq); |
| 120 | }); |
| 121 | if (epSqs.length == 0) |
| 122 | return moves; |
| 123 | for (let sq of epSqs) |
| 124 | { |
| 125 | if (this.subTurn == 1 || (epSqs.length == 2 && |
| 126 | // Was this en-passant capture already played at subturn 1 ? |
| 127 | // (Or maybe the opponent filled the en-passant square with a piece) |
| 128 | this.board[epSqs[0].x][epSqs[0].y] != V.EMPTY)) |
| 129 | { |
| 130 | if (sq.x == x+shiftX && Math.abs(sq.y - y) == 1) |
| 131 | { |
| 132 | let epMove = this.getBasicMove([x,y], [sq.x,sq.y]); |
| 133 | epMove.vanish.push({ |
| 134 | x: x, |
| 135 | y: sq.y, |
| 136 | p: 'p', |
| 137 | c: this.getColor(x,sq.y) |
| 138 | }); |
| 139 | moves.push(epMove); |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | return moves; |
| 145 | } |
| 146 | |
| 147 | play(move, ingame) |
| 148 | { |
| 149 | if (!!ingame) |
| 150 | { |
| 151 | move.notation = [this.getNotation(move), this.getLongNotation(move)]; |
| 152 | // In this special case, we also need the "move color": |
| 153 | move.color = this.turn; |
| 154 | } |
| 155 | move.flags = JSON.stringify(this.aggregateFlags()); |
| 156 | let lastEpsq = this.epSquares[this.epSquares.length-1]; |
| 157 | const epSq = this.getEpSquare(move); |
| 158 | if (lastEpsq.length == 1) |
| 159 | lastEpsq.push(epSq); |
| 160 | else |
| 161 | { |
| 162 | // New turn |
| 163 | let newEpsqs = [epSq]; |
| 164 | if (this.startAtFirstMove && this.moves.length == 0) |
| 165 | newEpsqs.push(undefined); //at first move, to force length==2 (TODO) |
| 166 | this.epSquares.push(newEpsqs); |
| 167 | } |
| 168 | V.PlayOnBoard(this.board, move); |
| 169 | if (this.startAtFirstMove && this.moves.length == 0) |
| 170 | this.turn = "b"; |
| 171 | // Does this move give check on subturn 1? If yes, skip subturn 2 |
| 172 | else if (this.subTurn==1 && this.underCheck(this.getOppCol(this.turn))) |
| 173 | { |
| 174 | this.epSquares[this.epSquares.length-1].push(undefined); |
| 175 | this.turn = this.getOppCol(this.turn); |
| 176 | move.checkOnSubturn1 = true; |
| 177 | } |
| 178 | else |
| 179 | { |
| 180 | if (this.subTurn == 2) |
| 181 | this.turn = this.getOppCol(this.turn); |
| 182 | this.subTurn = 3 - this.subTurn; |
| 183 | } |
| 184 | this.moves.push(move); |
| 185 | this.updateVariables(move); |
| 186 | if (!!ingame) |
| 187 | move.hash = hex_md5(this.getFen()); |
| 188 | } |
| 189 | |
| 190 | undo(move) |
| 191 | { |
| 192 | this.disaggregateFlags(JSON.parse(move.flags)); |
| 193 | let lastEpsq = this.epSquares[this.epSquares.length-1]; |
| 194 | if (lastEpsq.length == 2) |
| 195 | { |
| 196 | if (!!move.checkOnSubturn1 || |
| 197 | (this.startAtFirstMove && this.moves.length == 1)) |
| 198 | { |
| 199 | this.epSquares.pop(); //remove real + artificial e.p. squares |
| 200 | } |
| 201 | else |
| 202 | lastEpsq.pop(); |
| 203 | } |
| 204 | else |
| 205 | this.epSquares.pop(); |
| 206 | V.UndoOnBoard(this.board, move); |
| 207 | if (this.startAtFirstMove && this.moves.length == 1) |
| 208 | this.turn = "w"; |
| 209 | else if (move.checkOnSubturn1) |
| 210 | { |
| 211 | this.turn = this.getOppCol(this.turn); |
| 212 | this.subTurn = 1; |
| 213 | } |
| 214 | else |
| 215 | { |
| 216 | if (this.subTurn == 1) |
| 217 | this.turn = this.getOppCol(this.turn); |
| 218 | this.subTurn = 3 - this.subTurn; |
| 219 | } |
| 220 | this.moves.pop(); |
| 221 | this.unupdateVariables(move); |
| 222 | } |
| 223 | |
| 224 | // NOTE: GenRandInitFen() is OK, |
| 225 | // since at first move turn indicator is just "w" |
| 226 | |
| 227 | // No alpha-beta here, just adapted min-max at depth 2(+1) |
| 228 | getComputerMove() |
| 229 | { |
| 230 | if (this.subTurn == 2) |
| 231 | return null; //TODO: imperfect interface setup |
| 232 | |
| 233 | const maxeval = V.INFINITY; |
| 234 | const color = this.turn; |
| 235 | const oppCol = this.getOppCol(this.turn); |
| 236 | |
| 237 | // Search best (half) move for opponent turn |
| 238 | const getBestMoveEval = () => { |
| 239 | let moves = this.getAllValidMoves(); |
| 240 | if (moves.length == 0) |
| 241 | { |
| 242 | const score = this.checkGameEnd(); |
| 243 | if (score == "1/2") |
| 244 | return 0; |
| 245 | return maxeval * (score == "1-0" ? 1 : -1); |
| 246 | } |
| 247 | let res = (oppCol == "w" ? -maxeval : maxeval); |
| 248 | for (let m of moves) |
| 249 | { |
| 250 | this.play(m); |
| 251 | this.turn = color; //very artificial... |
| 252 | if (!this.atLeastOneMove()) |
| 253 | { |
| 254 | const score = this.checkGameEnd(); |
| 255 | if (score == "1/2") |
| 256 | res = (oppCol == "w" ? Math.max(res, 0) : Math.min(res, 0)); |
| 257 | else |
| 258 | { |
| 259 | // Found a mate |
| 260 | this.turn = oppCol; |
| 261 | this.undo(m); |
| 262 | return maxeval * (score == "1-0" ? 1 : -1); |
| 263 | } |
| 264 | } |
| 265 | const evalPos = this.evalPosition(); |
| 266 | res = (oppCol == "w" ? Math.max(res, evalPos) : Math.min(res, evalPos)); |
| 267 | this.turn = oppCol; |
| 268 | this.undo(m); |
| 269 | } |
| 270 | return res; |
| 271 | }; |
| 272 | |
| 273 | let moves11 = this.getAllValidMoves(); |
| 274 | let doubleMoves = []; |
| 275 | // Rank moves using a min-max at depth 2 |
| 276 | for (let i=0; i<moves11.length; i++) |
| 277 | { |
| 278 | moves11[i].eval = (color=="w" ? -1 : 1) * maxeval; |
| 279 | this.play(moves11[i]); |
| 280 | if (this.turn != color) |
| 281 | { |
| 282 | // We gave check with last move: search the best opponent move |
| 283 | doubleMoves.push({moves:[moves11[i]], eval:getBestMoveEval()}); |
| 284 | } |
| 285 | else |
| 286 | { |
| 287 | let moves12 = this.getAllValidMoves(); |
| 288 | for (let j=0; j<moves12.length; j++) |
| 289 | { |
| 290 | this.play(moves12[j]); |
| 291 | doubleMoves.push({ |
| 292 | moves:[moves11[i],moves12[j]], |
| 293 | eval:getBestMoveEval()}); |
| 294 | this.undo(moves12[j]); |
| 295 | } |
| 296 | } |
| 297 | this.undo(moves11[i]); |
| 298 | } |
| 299 | |
| 300 | doubleMoves.sort( (a,b) => { |
| 301 | return (color=="w" ? 1 : -1) * (b.eval - a.eval); }); |
| 302 | let candidates = [0]; //indices of candidates moves |
| 303 | for (let i=1; |
| 304 | i<doubleMoves.length && doubleMoves[i].eval == doubleMoves[0].eval; |
| 305 | i++) |
| 306 | { |
| 307 | candidates.push(i); |
| 308 | } |
| 309 | |
| 310 | const selected = doubleMoves[_.sample(candidates, 1)].moves; |
| 311 | if (selected.length == 1) |
| 312 | return selected[0]; |
| 313 | return selected; |
| 314 | } |
| 315 | |
| 316 | getPGN(mycolor, score, fenStart, mode) |
| 317 | { |
| 318 | let pgn = ""; |
| 319 | pgn += '[Site "vchess.club"]<br>'; |
| 320 | const opponent = mode=="human" ? "Anonymous" : "Computer"; |
| 321 | pgn += '[Variant "' + variant + '"]<br>'; |
| 322 | pgn += '[Date "' + getDate(new Date()) + '"]<br>'; |
| 323 | pgn += '[White "' + (mycolor=='w'?'Myself':opponent) + '"]<br>'; |
| 324 | pgn += '[Black "' + (mycolor=='b'?'Myself':opponent) + '"]<br>'; |
| 325 | pgn += '[FenStart "' + fenStart + '"]<br>'; |
| 326 | pgn += '[Fen "' + this.getFen() + '"]<br>'; |
| 327 | pgn += '[Result "' + score + '"]<br><br>'; |
| 328 | |
| 329 | let counter = 1; |
| 330 | let i = 0; |
| 331 | while (i < this.moves.length) |
| 332 | { |
| 333 | pgn += (counter++) + "."; |
| 334 | for (let color of ["w","b"]) |
| 335 | { |
| 336 | let move = ""; |
| 337 | while (i < this.moves.length && this.moves[i].color == color) |
| 338 | move += this.moves[i++].notation[0] + ","; |
| 339 | move = move.slice(0,-1); //remove last comma |
| 340 | pgn += move + (i < this.moves.length-1 ? " " : ""); |
| 341 | } |
| 342 | } |
| 343 | pgn += "<br><br>"; |
| 344 | |
| 345 | // "Complete moves" PGN (helping in ambiguous cases) |
| 346 | counter = 1; |
| 347 | i = 0; |
| 348 | while (i < this.moves.length) |
| 349 | { |
| 350 | pgn += (counter++) + "."; |
| 351 | for (let color of ["w","b"]) |
| 352 | { |
| 353 | let move = ""; |
| 354 | while (i < this.moves.length && this.moves[i].color == color) |
| 355 | move += this.moves[i++].notation[1] + ","; |
| 356 | move = move.slice(0,-1); //remove last comma |
| 357 | pgn += move + (i < this.moves.length-1 ? " " : ""); |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | return pgn; |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | const VariantRules = MarseilleRules; |